Having driven 1000's of miles a year for work, I don't know what I would do without some distraction of sound.
So, the radio failed a while back, and I needed something,
anything to listen to in the car. The best that came to mind was a clock-radio plugged into a small inverter (cig-lighter). No presets, one speaker, and always blinked 12:00. The alternative is a Walkman, a bunch of rechargeable batteries, and (depending on local laws), earphones or a small speaker.
In rentals, I tend to carry my laptop with all of my CDs uploaded. The small speakers are good enough for entertainment and a 3-hour batt life. Sat-radio beats everything, IMO.
So, can you hook the radio to a separate, small battery that can be recharged from the grid? But, I don't know of many hotels with an outlet in the parking lot, though
-Rick